Stored procedure does not work in MySQL

DELIMITER $$

DROP PROCEDURE IF EXISTS `pawn`.`simpleproc`$$
CREATE DEFINER=`root`@`localhost` PROCEDURE  `pawn`.`simpleproc`(OUT param1 int, inout incr int)
BEGIN
declare incr Integer;
    set incr= incr+1;
    SELECT count(*) into param1 FROM pawnamount;
 END $$

This is my code to create a stored procedure....It's created.. For execute..

call simpleproc(@param1,@incr);
select @param1,@incr

The Result will be null values.. It is the simple one.. I've tried many times.But,I get null values only..

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DECLARE incr INT;                            -- incr is NULL here, add DEFAULT 0  if you want it to have a value
SET incr = incr + 1                          -- NULL + 1 is still NULL
SELECT COUNT(*) INTO param1 FROM pawnamount; -- If the table pawnamount is empty, it generates an empty set, which in a parameter assignment becomes NULL.